Favism-induced methemoglobinemia in a G6PD deficient male with a subsequent hemolytic cascade, a therapeutic challenge: Case report and review of literature

Favism: Clinical Features at Different Ages

Favism is a hemolytic disease due to the ingestion of fava beans in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. There is wide inter- and intra-individual variability in the development of hemolytic crisis, and several factors influence it: quantity, quality, ripeness of fava beans, and age of onset. In this narrative review of case reports and case series, we reported the predisposing factors and clinical features for four different age groups classified as follows: pregnant women and infants (i.e., exclusively breastfed children); children, from weaned to 11 years; preadolescents and adolescents, from 11 to 18 years; and adults (18 years and older). Some symptoms developed only in specific age groups: death in infants; visual impairment in children; systolic murmur in infants, children, and adolescents; and renal failure in adults. In youngest children or pregnant women the severity is the highest. Some other symptoms were present in all: jaundice, increased bilirubin, splenomegaly, hepatomegaly, discolored urine, tachycardia, pallor, abdominal pain, malaise, vomit, nausea, and dizziness. Laboratory findings are characterized by anemia, reticulocytosis, elevated bilirubin level, and sometimes urinary urobilinogen and methemoglobinemia. In most cases the symptomatology is self-limited and does not release sequelae, but hospitalization and transfusion are often required.

Acute hemolysis and methemoglobinemia secondary to fava beans ingestion in a patient with G6PD deficiency: A case report of a rare co-occurrence

RATIONALE

Favism is a well-known cause of acute hemolytic anemia. Rarely, methemoglobinemia can also happen because of fava bean ingestion in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Few cases with this co-occurrence have been reported in the literature.

PATIENT CONCERNS

We report a case of a 47-year-old patient who presented with jaundice that started 2 days after eating fava beans.

DIAGNOSES

Laboratory investigations revealed anemia with evidence of hemolysis (high reticulocytes count, high indirect bilirubin, bite cells in peripheral smear). Blood gases showed high methemoglobin level. Reduced level of G6PD enzyme confirmed the diagnosis of G6PD deficiency.

INTERVENTION

The patient was kept on supplemental oxygen. He was counselled to avoid food and drugs that can cause acute hemolysis.

OUTCOMES

Oxygen saturation improved gradually. The patient was discharged without any complications after 2 days.

LESSONS

Patients with G6PD deficiency can develop both acute hemolytic anemia and methemoglobinemia secondary to fava beans ingestion. These patients should not receive methylene blue to avoid worsening hemolysis.